This invention relates to a medical device, particularly an endoscopic medical device, which is designed to facilitate the surgical procedures of tissue approximation and vessel ligation.
As medical and hospital costs continue to increase, surgeons are constantly striving to develop advanced surgical techniques. Advances in the surgical field are often related to the development of operative techniques which involve less invasive surgical procedures and reduce overall patient trauma. In this manner, the length of hospital stays can be significantly reduced, and therefore the hospital and medical costs can be reduced as well.
One of the truly great advances in recent years to reduce the invasiveness of surgical procedures is endoscopic surgery. Endoscopic surgery involves the use of an endoscope, which is an instrument permitting the visual inspection and magnification of any cavity of the body. The endoscope is inserted through a tube, conventionally referred to as a cannula, after puncture of a hole into the soft tissue protecting the body cavity. The hole is made with a trocar, which is a sharp-pointed instrument. The trocar includes an obturator, or cutting implement, which is slideably and removably disposed within a trocar cannula. The obturator will puncture a hole in the tissue equal in size to the inner diameter of the trocar cannula. After puncture, the obturator can be slideably withdrawn from the trocar cannula. The surgeon can then perform diagnostic and therapeutic procedures at the surgical site with the aid of specialized instrumentation designed to fit through the trocar cannula and additional trocar cannulas providing openings into the desired body cavity as may be required.
In many surgical procedures, suturing and ligating are required to close wounds. For example, suturing to approximate tissue, which requires the formation of a suture knot for placement of a stitch, is often required for proper healing of lacerations and surgical incisions. Additionally, ligating blood vessels to be cut within the surgical site is often necessary in numerous surgical procedures. The vessels may then be severed between the ligations. The primary reason for ligating the vessels is to maintain the surgical site free of an excess of blood and to reduce blood loss in the patient.
Conventionally, surgeons have closed blood vessels with ligatures, which are long, relatively straight strands of suture material. As is the case with the formation of a suture knot to place a stitch, the surgeon must manually tie a knot on the ligature after the ligature is looped around the vessel desired to be closed. Unfortunately, the formation of a knot on sutures and conventional ligatures is tedious and time-consuming during endoscopic surgical applications where a surgeon's manual operative techniques within the surgical site are severely restricted.
In more recent years, a ligature has been developed which is better adapted for endoscopic surgery. ENDOKNOT gut ligature is a device formed from a suture material of surgical catgut. The catgut ligature is securely fastened within a cannula at one end and attached to a needle at the other end. This device is described in the 1991 package insert for the product sold by Ethicon, Inc., which insert is entitled "ENDOKNOT Suture Made With Chromic Gut". Although ENDOKNOT gut ligature facilitates ligation of vessels through small incisions in bodily cavities, the surgeon is required to manually tie the ligature knot extracorporeally, i.e. outside the body, to ligate a vessel. This is a time consuming and laborious process, especially for inexperienced surgeons, and represents a significant disadvantage to the use of the ENDOKNOT ligature device during endoscopic surgery.
An improved device for ligation is described in European Patent Application 477,020, published Mar. 25, 1992. This device has a suture loop extending from the cannula. The loop is secured to the suture strand with a slip knot. This device eliminates the need to tie a knot extracorporeally, but the loop is extremely difficult to maneuver and position during endoscopy. In addition, it is difficult to avoid undesirably rotating the loop during use. Furthermore, the device is designed only for ligation, and not for tissue approximation as well.
A similar device to that described in the European patent application discussed above is disclosed in U.S. Pat. No. 5,129,912. This device has a pre-looped suture and needle for tissue approximation, and means for applying tension on the suture knot. Unfortunately, this device suffers from similar deficiencies because it too is difficult to maneuver and position during endoscopy.
Another attempt to avoid the need for manually tying the knot extracorporeally for ligation or tissue approximation is described in U.S. Ser. No. 728,443, filed Jul. 11, 1991. This reference describes a device which has a partially tightened knot secured around a cannula. The knot can be slid down the cannula onto a suture strand to make a loop which can then be subsequently tightened into a secure knot. Unfortunately, in operation the user must thread the suture strand up through the cannula before sliding the partially tightened knot down the cannula to make the loop. This threading operation is undesirable because it is time consuming and tedious. A similar device is shown in U.S. Pat. No. 2,012,776.
In view of the significant deficiencies of the prior art, an endoscopic suturing device having a suture loop which avoids manually tying knots extracorporeally, and is designed to easily manipulate and position the suture loop during use, would be highly desired within the medical community. Additionally, it would be highly desirable if such a design were designed which offered the flexibility for use to not only ligate vessels but also approximate tissue.